Treatment of textile materials



Patented Aug. 20, 1940 UNITED STATES PATENT OFFICE TREATMENT OF TEXTILEMATERIALS tion of Delaware No Drawing. Application August 1938, Serial 7Claims.

This invention relates to the treatment of textile materials comprisingfilaments, yarns, ribbons or the like of cellulose or regeneratedcellulose and especially high tenacity filaments, yarns,

5 ribbons and the like of regenerated cellulose.

By swelling regenerated cellulose textile materials, and particularlyregenerated cellulose textile materials formed by saponification oftextile materials having a basis of cellulose acetate or other celluloseesters, e. g. stretched cellulose ester materials which have beensaponified with solutions of caustic soda or other strong alkalies, theaffinity of the materials for cotton dyestuffs can be enhanced and theserimetric properties, e. g. flexibility and extensibility, can beimproved.

We have now found that particularly valuable results may be obtained inthis process, and any tendency of the treating solution to actdeleteriously on the regenerated cellulose may be reduced, if thematerials are treated with solutions of caustic soda or other strongalkali which contaln compounds capable of acting as buffers indyestuffwhich has an aflinity only for the regenerated cellulose yarns leavingthe cellulose ester yarns white. It is, therefore, of considerableimportance to be able to improve the afiinity of the regeneratedcellulose yarns for the dyestuffs without at the same time deleteriouslyaffecting the resist properties of the cellulose ester yarns. The strongalkali employed may be caustic soda, as indicated above, or it may belithium hydroxide, caustic potash or a quaternary ammonium compound suchas trimethyl benzyl ammonium hydroxide.

Particularly satisfactory results have been obtained by the use ofsugars as the buffering compounds and it is, therefore, preferred to usethese bodies. Various sugars may be used, for example,

cane sugar or other di-oses or poly-oses. Particularly good results havebeen obtained with the aid of glucose, dextrose, laevulose, galactoseand other mono-oses, and there may be employed crude products containingthese sugars, for ex- In Great Britain September 9,

ample, the mixture of glucose and laevulose obtainable by hydrolysingcane sugar or a'crude sugar containing the mixture obtainable by thehydrolysis of wood.

However, other buffering compounds may be 5 employed, and as examples ofsuch agents may be mentioned polyhydric alcohols, for example, mannitol,and also substances of weakly acidic character as, for example, theamino acids, e. g. the aliphatic amino acids, as, for example, glycineor the dior poly-peptides in which two or more acid or amino residuesare united, e. g. glycyl-glycine. Suitable amino acids or diorpoly-peptides are, for example, those readily obtainable by the acid oralkaline hydrolysis of proteins. Crude hydrolysis products obtainable byhydrolysing wool or other protein material with aqueous alkali may alsobe employed. Other substances are weak inorganic acids, e. g. boricacid, and, in general, there may be employed neutral or weakly acidsubstances which are capable of forming salts with alkalies.

The concentrations of the strong alkali and the buffering agent willdepend largely on the nature of the materials treated and of the alkaliused 25 as well as on the temperature at which it is desired to work. Ingeneral as the temperature is reduced the action of a givenconcentration of alkali'in increasing the dye aflinity is enhanced andat the same time the danger either of deleterious action of the solutionon the cellulose linkages and of saponification of cellulose estermaterials present in admixture with the cellulosic materials-is reduced.Low temperatures, e. g. below 10 C. or even below 5 or 0 C., e. g. downto 35 -5 C. are therefore preferred but it is possible to work at highertemperatures, e. g. 20 C. or higher. In general, concentrations ofaqueous caustic soda between 35% are most useful. Thus, valuable resultsare obtainable at temperatures below about 11 C. with solutionscontaining 5-30% of caustic soda and about 5-20% glucose andparticularly useful results are obtainable by the use of solutionscontaining 8-12% of caustic soda and about the same amount of glucose,at 45 temperatures below 5 C. and preferably in the neighborhood. of 0C. Lithium hydroxide can be used in similar concentrations but causticpotash must be more concentrated to get similar results and the same istrue of the quaternary ammonium bases. In general, the higher thetenacity of the materials treated the less rigorous need be theconditions toget the ,desired results. The time of treatment ispreferably very short, e. g. 1, z or 3 minutes but with more dilutesolu- 55 tions than those contemplated above a longer 1 time oftreatment is permissible, though this may introduce some danger ofsaponifying any cellulose ester materials present.

The alkaline medium containing the buffering compound may be applied toany form of textile material, e. g. textile material in the form ofyarns or other filamentary materials or in the form of fabrics, and maybe applied by any suitable method, e. g. by passing the textilematerials through a bath of the alkaline medium containing thebufieringcompound. It is desirable that the materials, immediately afterbeing contacted with the alkaline medium for the requisite time, shouldbe quickly washed in order to stop the action of the alkaline medium.

The following examples illustrate the invention:

Example 1 Regenerated cellulosic yarn made by the completesaponification of cellulose acetate yarn stretched to a considerableextent under the infiuence of steam is immersed for 1 minute in hankform in an aqueous bath containing 10% of caustic soda and 10% ofglucose at a temperature of 0 C. An aifinity for cotton dyes is impartedto the material, which, however, is not swollen to as great an extent asit would be in the absence of the glucose so that less risk of damagingthe material is present.

The temperature may be maintained at 10 C. instead of 0 C. or may bebetween 0 and 10 C.

Example 2 V The process is carried out as in Example 1 but employing abath containing 30% caustic soda and 15% glucose.

Example 3 The process is carried out as in Example 2 but employing asolution containing 20% of caustic soda and 10% glucose.

Example 4 Example 5 x A fabric treated according to Example 4 is dyed ina dye-bath containing 4% of Diphenyl F Scarlet 435 and 20% of commonsalt, these percentages being based on the weight of the material andthe bath volume being 40:1. The

regenerated cellulose yarn is dyed whereas the cellulose acetate yarnremains uncoloured. I

In the above examples, caustic soda can be replaced by lithiumhydroxide. Somewhat similar results can be obtained by employing in-"stead of caustic soda trimethyl benzyl ammonium hydroxide in 20%concentration, the time, temperature and concentration of the glucosebeing the .same. If caustic potash be substituted for the caustic soda,higher concentrations and/or times are required and the concentration ofthe glucose may be reduced. Instead of glucose may be used, for example,glycine, glycyl-glycine and sugars such as laevulose, dextrose andgalactose.

In the examples, all the percentages are by weight.

The invention, as indicated above, is applicable to the treatment ofcellulosic textile materials. generally. It is of particular importance,however, in connection with materials comprising filaments, yarns,ribbons or the like of regenerated cellulose and having a high tenacity,i. e. a tenacity higher than that obtainable by ordinary spinningprocesses without a spacial stretching operation. The lower limit forhigh tenacity yarns and the like may be taken as about 1.5 grams perdenier. The advantages of the present invention are best seen, however,with materials of higher tenacity than this, e. g. 1.75-2, 3, 4 or moregrams per denier.

The invention has been described with particular reference to increasingthe affinity of the materials for cotton dyes. The increase in afiinityobtained however is accompanied by an increase in affinity for otherdyes especially vat dyes in alkaline solution.

Having described our invention, what We desire to secure by LettersPatent is:

1. Process for the production of improved artificial materials whichcomprises treating materials containing high tenacity filaments, fibers,yarns or the like of regenerated cellulose in admixture with filaments,fibers, yarns or the like of an organic ester of cellulose with a 4-35%aqueous solution of caustic soda containing 5-20% of a bufiering agentat a temperature below 20 C. to increasethe aflinity of the regeneratedcellulose for cotton dyes without saponifying the cellulose ester andwithout deleteriously affecting the regenerated cellulose constituent.

2. Process for the production of improved artificial materials whichcomprises treating materials containing high tenacity filaments, fibers,yarns or the like of regenerated cellulose in admixture with filaments,fibers, yams or the like of an organic ester of cellulose with a 4-35%aqueous solution of caustic soda containing 520% of sugar at. atemperature below 20 C. to increase the afiinity of the regeneratedcellulose for cotton dyes without saponifying the cellulose ester andwithout deleteriously affecting the regenerated cellulose constituent.

3. Process for the production of improved artificial materials; whichcomprises treating materials containing high tenacity filaments, fibers,yarns or the like of regenerated cellulose in admixture with filaments,fibers, yarns or the like of cellulose acetate with a 4-35% aqueoussolution of caustic soda containing 5-20% 01 a buffering agent at atemperature below 20 C. to increase the aflinity of the regeneratedcellulose for cotton dyes without saponifying the cellulose acetate andwithout deleteriously affecting the regenerated cellulose constituent.

'4. Process for the production of improved artificial materials whichcomprises treating materials containing high tenacity filaments, fibers,yarns or the like of regenerated cellulose in ad-- mixture withfilaments, fibers, yams or the like of cellulose acetate with a 5-30%aqueous solution of caustic soda containing 5-20% of glucose at atemperature below 11 C. to increase the aiflnity of the regeneratedcellulose for cotton dyes without saponifying the cellulose acetate andwithout, deleteriously affecting the regenerated cellulose constituent.

5. Process for the production, of improved artificial materials whichcomprises treating materials containing filaments, fibers, yarns or thelike of regenerated cellulose of tenacity at least 2 grams per denier inadmixture with filaments, fibers, yarns or the like of cellulose acetatewith a 5-30% aqueous solution of caustic soda containing 520% of glucoseat a temperature below 11 C. to increase the affinity of the regeneratedcellulose for cotton dyes without saponifying the cellulose acetate andwithout deleteriously affecting the regenerated cellulose constituent.

6. Process for the production of improved artificial materials whichcomprises treating materials containing high tenacity filaments, fibers,yarns or the like of regenerated cellulose in admixture with filaments,fibers, yarns or the like of cellulose acetate with an 842% aqueoussolution of caustic soda containing 15-12% of glucose at a temperaturebelow 5 C. to increase the affinity of the regenerated cellulose forcotton dyes without saponifying the cellulose acetate and withoutdeleteriously afiecting the regenerated cellulose constituent.

7. Process for the production of improved artificial materials whichcomprises treating materials containing filaments, fibers, yarns or thelike of regenerated cellulose of tenacity at least 2 grams per denier inadmixture with filaments, fibers, yarns or the like of cellulose acetatewith an 812% aqueous solution of. caustic soda containing 13-12% ofglucose at a temperature below 5 C. to increase the afinity of theregenerated cellulose for cotton dyes without saponifying the celluloseacetate and without deleteriously afiecting the regenerated celluloseconstituents.

ALEXANDER JAMES WESSON. GEORGE HOLLAND ELLIS.

